1. Field
Example embodiments relate to a display device, and more particularly, to a reflective display device including polymer-dispersed liquid crystals (PDLCs).
2. Description of the Related Art
Devices using polymer-dispersed liquid crystals (PDLCs) may have a structure in which polymers and liquid crystals are uniformly distributed, and when an electric field is applied to the PDLCs, optical refractive indexes of the polymers and the liquid crystals are changed. In more detail, when the electric field is not applied to the PDLCs, liquid crystal molecules may be randomly oriented, and light incident on the PDLCs is scattered due to a difference between a refractive index of the polymers and a refractive index of the liquid crystals. However, when the electric field is applied to the PDLCs, the liquid crystal molecules may be arrayed in parallel with the electric field, and light incident on the PDLCs passes through the PDLCs due to a match between the refractive index of the polymers and the refractive index of the liquid crystals. In this manner, the PDLCs may scatter or transmit light by adjusting the difference between the refractive index of the polymers and the refractive index of the liquid crystals by applying an electric field applied thereto. Thus, the PDLCs may be usefully applied to a reflective display device that displays information or an image by using an external light source.
An absorption plate for absorbing light that passes through the PDLCs may be used in the reflective display device including the PDLCs. However, in the reflective display device using the absorption plate, light that is scattered from the PDLCs and then is incident on the absorption plate is dissipated such that a reflection efficiency deteriorates. In order to reduce the deterioration of the reflection efficiency, a specular plate may be used to specularly reflect light that passes through the PDLCs. However, in a case of using the specular plate, if a viewer is positioned at an angle at which incident light is specularly reflected, visibility of the reflective display device considerably deteriorates.